As mobile services increase exponentially, mobile networks are evolving toward 5G networks. Larger bandwidth and higher spectral efficiency are required in a 5G network, so as to support the explosive growth of services. Using an ultra dense small-cell network with low power can effectively provide a larger data volume. At present, a multi-connection technology involving a conventional network (for example, a Long Term Evolution LTE network) and a 5G network has been proposed in the industry. The conventional network provides network coverage to increase mobility robustness, and the 5G network provides a higher transmission rate to increase a system capacity. However, as a coverage area of a cell decreases, user equipment (UE) is handed over more frequently between cells or between eNodeBs that serve cells. As a result, mobility of the user equipment between multiple cells seriously deteriorates.
Therefore, a method for handover between secondary eNodeBs is urgently needed, to relieve the problem of mobility deterioration resulting from frequent handover between cells because cell coverage of a secondary eNodeB in a 5G network is excessively small.